The hex jam nut is thinner than the standard hex nut. It is tightened against the work surface, with a standard hex nut tightened behind it to keep it firmly in place. The heavy hex jam nut is thinner than the heavy hex nut, and is wider across the flats and thicker than hex jam nuts.

The hex slotted nut features slots for the insertion of a small pin, for locking purposes. It is as thick as the standard hex nut.

The hex thick slotted nut is at least 10 percent thicker than the hex slotted nut. The width and depth of slots are the same, however, as the hex slotted nut. The heavy hex slotted nut is as thick as the heavy hex nut. It is both wider across the flats and thicker than hex slotted nuts.

The hex castle nut features slots for the insertion of a small pin, for locking purposes. The raised segments between the slots on this hex nut variation resemble the turrets of a castle. It is at least 10 percent thicker than the hex slotted nut. The width and depth of slots are the same, however, as on the hex slotted nut.